Doak Walker, the 1948 Heisman Trophy winner and one of college football's legendary heroes, died yesterday at Routt Hospital in Steamboat Springs, Colo. He was 71.

The cause was complications from the paralysis he suffered in a skiing accident last Jan. 30 in Steamboat Springs, where he lived, the hospital said. After hitting a change in terrain, Walker traveled 20 to 30 feet in the air and tumbled 75 feet, and he was paralyzed from the neck down.

In the years immediately following World War II, when Texas was feeling big about itself in so many ways, the state's biggest sports figure was Doak Walker, a handsome, humble hero who could do so much with a football. He played for Southern Methodist University in his home city of Dallas, and twice the Cotton Bowl there was enlarged to accommodate the crowds that came to watch him.

When the Heisman Trophy, voted annually to the best college player, went to Walker following the 1948 season, Ewell and Emma Walker, his parents, who were teachers, accompanied him to New York to receive the award at a banquet in the Downtown Athletic Club. In those days, that was a big trip. On the flight home, Emma Walker said, ''All of this because one little blue-eyed boy could run with the football.''

Walker was small for big-time football at 5 feet 11 inches and 170 pounds. He played four seasons for Southern Methodist between 1945 and 1949 and six more for the Detroit Lions of the National Football League. He quit after the 1955 season, saying, ''I want to get out while I have all my teeth and both my knees.''

He was elected to the College Football Hall of Fame in 1959 and the Pro Football Hall of Fame in 1986. When the Pro Football Hall of Fame admitted him, a Lions teammate, Gil Mains, said: ''At last. Now we can relax.''

Mains and other old Lions had lobbied hard and long for Walker's inclusion, which had been delayed perhaps because he played so briefly as a pro. However, he left his mark.

He led the N.F.L. in scoring his first season, when he was named the league's rookie of the year, and he was chosen for the Pro Bowl five times. With Walker as their running back, the Lions won the N.F.L. championship in 1952 and 1953. They were the league's dominant team of the 1950's.

The leader of that team was the quarterback, Bobby Layne, Walker's teammate at Highland Park High School in Dallas and an opponent in two epic college games between Southern Methodist and Texas. They became lifelong friends.

Walker was installed as the first-string tailback in Coach Matty Bell's double-wing offense upon entering S.M.U., and in his first game he played the full 60 minutes against Texas. Walker scored his team's only touchdown and kicked the extra point, but a late touchdown pass by Layne won the game for Texas, 12-7.

After Army service in 1946, Walker returned to Southern Methodist for glorious seasons in 1947 and 1948, when the team lost only once, and for a lesser season in 1949 because of injuries.

Late in the 1947 season, unbeaten Southern Methodist trailed Texas Christian, 12-0, when Walker scored a touchdown on a 65-yard run and set up another for a 13-12 lead. But Texas Christian scored with 90 seconds left for a 19-13 lead, and a Texas Christian tackle, Harold Kilman, said, ''Now what are you going to do, Doak?''

''Score again,'' Walker said. Whereupon he returned the ensuing kickoff 65 yards to the Texas Christian 35-yard line.

S.M.U. scored on a pass play as time ran out but Walker missed the extra-point kick and the game ended in a 19-19 tie.

Walker, who had accounted for 475 yards in the game, often said later, ''All I remember is, I missed the kick.''

By then, Southern Methodist had moved its games from a 17,700-seat campus stadium to the Cotton Bowl on the grounds of the Texas State Fair. Over the next two years, upper decks were built on both sides and the capacity of 45,507 was increased to 67,431. A plaque went up that read, ''The House That Doak Built.''

In 1947, when Walker made both conversion kicks, Southern Methodist defeated Texas and Layne there, 14-13. That gave Southern Methodist the conference championship and a berth in the Cotton Bowl game there on New Year's Day, Walker's 21st birthday. That game against Penn State ended in a 13-13 tie.

Walker ran with the football, passed it, caught it and kicked it. In 30 regular-season college games, he scored 288 points.

After football, Walker was a sales executive with an electrical construction company and then founded Walker Chemicals in Denver, a company he sold upon retirement. He had married a college classmate, Norma Peterson, in 1950. He is survived by their four children, Laurie, Kris, Russell Doak and Scot Alexander, and four grandchildren. The marriage ended in divorce.

Later, Walker moved to Steamboat Springs, Colo., and in 1969 he married Skeeter Werner, who had been an Olympic skier and New York model. They ran a ski shop in Steamboat Springs.

Werner's brother, Buddy Werner, was the United States' best Alpine skier at the 1964 Winter Olympic Games. He was killed shortly after by an avalanche while skiing in Italy.

The mountain in Steamboat Springs was then renamed Mount Werner. It was there that Walker, at age 71, fell and was paralyzed.

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